Device Models: Tapo L535B, Tapo L430C

Firmware: Latest

App Version: Android (Samsung)

The Issue:

The Tapo App’s logic for Sunrise Automations is fundamentally flawed. Instead of initializing the bulb at the lowest possible voltage $(\approx 1\%)$ to begin a gradient, the app sends a "Power On" command that defaults to the "Last Known State." Observed Behavior:

1. Preparation: Use a bulb at 80% brightness in the evening, then turn it off.

2. Trigger: Sunrise Automation starts at the scheduled time.

3. The Failure: The bulb ignites instantly at 80% brightness. It then "locks" this as the floor for the automation.

4. The Result: The gradient only applies from 80% to 100% over the duration of the timer. The bulb never resets to 1%, resulting in an instant "flashbang" effect that defeats the purpose of a circadian wake-up feature.

Technical Root Cause:

The Tapo App appears to be prioritizing the bulb's last_known_brightness or default_state variable over the Sunrise Automation’s intended starting parameters. It fails to send a "Force 1% Brightness" initialization packet simultaneously with the "Power On" trigger.

Current (Inadequate) Manual Workarounds:

1. Manual "Priming" Step: Users must manually create a "Step 1" in the automation to Force 1% Brightness at least one minute before the Sunrise command triggers. This "primes" the bulb at the lowest level so the subsequent Sunrise ramp executes from 1% rather than a high previous state.

2. Global "Custom Default" State: One can set the bulb's hardware "Default State" to 1%. However, this means the light always turns on at 1% during normal daytime use, forcing the user to manually adjust the brightness level every time they enter the room.

Conclusion: Neither workaround is acceptable for a "Smart" lighting system. The firmware should automatically prioritize a 1% initialization only when a Sunrise/Gradient trigger is detected.